SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '988ed8385703fc7e17dcef9374fc3b31c78434a221645b8db69dd6064017804c' 
  AND token = 'c7HIBAW3IoqfKva4LOwZvW0nk1sG3eNpL3KKLnNDfO4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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