SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b98bb19c617affb3dfed3433f77b953eb56003c090c477aaa73378ca983b5624' 
  AND token = 'ak7ULkiK2W5wqkipeaJd5juMmkxwoPl5oHdo0GcoW94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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