SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25d00cab78b731ba838bbc2176a32c6d9ac0823b112ea0fbaca839147edeaf14' 
  AND token = '9GZ3P+qsF1cW+qYzVe8QqvcitpTlFvp80tz6jAnP3fw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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