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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3642c5a96b5ba9aa8700771b1b72abb7fc6c4eeb88ed8db8dbf4c2d8e6f1a1c' 
  AND token = 'Ls1eTdhwy/fWKvaQEo42nmW/tawD/dOVGTH3VtvTryg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}