SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '365b1fb636b352579405e6f866f62a958f6a245c483902d0ccf07b9dd3aa4517' 
  AND token = 'HmlmVV2jCoUPK7wMsmOSdb7oDfo+/8HJvBdvBhXdIn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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