SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd7c276c30db5cf5624958c4a777147b2921cc395effac8b42e63dca00231e96c' 
  AND token = 'Rc8NTUpN1mrPKTfQWudFfDm0IPOM2UuMni8YPJ8AVnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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