SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ea61d17cf1cf69cce1e017e824f9de6bd8ce671ebbd58bcbbcfe54144a1d0f6' 
  AND token = 'GUwFMzjk3/omrVyLJwmfY4WOpHuWWzlbGHXxrIBrQdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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