SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2164c8d9964b7c19c03cb8073532da1bccef1b7e57901a210a9c8960e724b4d0' 
  AND token = 'P8rQyeh317ZJJZ6tHG9YX5cBF6cLkxMWOhcBzT+vKgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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