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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c030cff5ddaa0669957171d2757d5ec76cdb39bcbd4baaec036e9f244c33822b' 
  AND token = 't0MiVNMIuFtyE3fJvEJnTretN4VTJ6rriBsnkibiIQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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