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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2071dbbc90d698ef2d613c6a4c1e4206235dc6bee61c8e9b22d2cc0494d240a9' 
  AND token = 'ysCsf8JLAiv/EYQ8FVvypazT0sBtDsAF0xfYd2NAsOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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