SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14a95aed6c80ea2f31f9cd126405922bc6042706bbeb152d9926c23a03147b20' 
  AND token = 't0yreogV+MmnvbcB52P5JlWLjl0nxOHIYOkC9gI6Zyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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