SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd94ce7af852df0e77992552202f473b3b2c138ad748028d0156e15f213a9996f' 
  AND token = 'l80cA9fEIudjerMn5v3+id0lB7dq3YyxuOGwZqwuo2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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