Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'cb4deaad8118f251b120d0c1f1d28ecf186d64ff6a69f40d19d0316a66c8c396' 
  AND token = 'I+Rc4Byxi3IcC5Pwb4Bv7IOEC6TGkLlrBOVL6fwVzCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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