SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '5b5fd24d7ab7eda78a60adb25409605a9175c0b7406f195d7a22595c5a752647' 
  AND token = 'bBDZ4VbwFADZ/URfduPvzP/rWq9Ek9QvNxYRGMvSHJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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