SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e30d36b97d919183a7f90de02f975f44b6c043bdf5ce7b04631444cb32dd7fe7' 
  AND token = 'zQ9v6hbeWt+fu7YchA+vMWu5TEGb+XCphlZZbBN0VOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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