Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd69a0d8de6337aa3e1f27204ec58a0f306c63bf4c79d3803aaffac9087f6b9e2' 
  AND token = 'TBYOCTIwrhQLLsU6bH82HEGhbuBhRAMZO4aOQLglGus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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