SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bc7c413fd5f3e5dec1466d83b60ac3fa303b9c831b25857d2b2d72af6fbf33c' 
  AND token = 'yIh9jKgq0YJXA3n+wR1EpUwHXRI8U52LFBvuWwSniYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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