SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e78d7d69ea18c38ae9d0cd72db59da41678cf44578fde436aa7df799a4df13c' 
  AND token = 'OrdbAE3zPxJ2MG0Akh35YtmySyA15Yfwon9yF5H68F8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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