SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'aa5d1ad429fdc461c7be08ee0545f7f2d26db39ed0d2b086a36a911919d213c8' 
  AND token = 'LMX8QHp74Y5CDD3NJAGIjBtHu60N1IzE+CI3pO8Du6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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