SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84e14399dfa3aebd45016b43c433426660c84900f3eba19d1f5160fc40d8bf5d' 
  AND token = 'jiYn+lmMRatsWDxZnyDSmTfXYhRESGZ9TFZh4Bqraqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}