SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04827a902fc6edcd65afd5b970fe245dd6b3347166fa53aa7e94649da7746128' 
  AND token = 'MQqKfEbyhzblDiS6UKbdQxN87NjAl0OFzW55pGInFSE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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