SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e0c2cac8c2684f8e2a0ab731672f8ae630fb6184f79922b82ee88ac504674897' 
  AND token = 'bus8v8FdOzuD+Mrl+PmqHGrUlFetdA/0ZuboxmBD2AA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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