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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '987c8bb54b9d4a627c74989d00672e1c891e9af3e6bf1882872fb08ef6de149f' 
  AND token = 'VT2FRVnPQUjC+dlkoS/JURpSJIeOFgvyCsJXXiu9UDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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