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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffb0ad9b0c542df4cbe285f4b45fbbcfb7d5da39ac39c35c760f758d99586ea9' 
  AND token = 'kl9+DYctNFPHFaVh8RTcJI3tNUF0LxS5eZOHpeqHAF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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