SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83dc18c5f831a5a49a964eaa5aef315d16e90c636ef09dad354aa06fb8f0a65a' 
  AND token = 'yB5S8bfEv1VXxOeLk+e1Ga0nA8lKax65z0fuBCuyOvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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