SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd370c49fc056c411373d6e7cf4a311c0bc3a57adbaddb53b040cae04b223a7d2' 
  AND token = 'uJbz3fHQEGbM7ChlxHkVZEmz/WOB3qCCIMvxoGuU3QQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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