SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da5cc457bc45c9cecc3fac1ccd764bf6a2d75013949611e1ca6f0f634eeaf75e' 
  AND token = 'M8UyED16Ez18mQcmWlbiWDkRg/6dm/lrlgE3hboHxWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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