SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a05122aab9c8f550f523e94c859b663391cc2faf560201c4d05d65edc1b044d9' 
  AND token = 'uIK9QYowRPHhmWnh7367dC0+9gPNA4AvzAlhdNwrnCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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