SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd81f9647281cec3f7b35db1fd27cf2c37f90ee4b44f94009da857203c1c98f22' 
  AND token = 'xgp1iW1NIwzWO8Uj0wSZmiCkU1gvFwl/h45MrHrXLM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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