SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7055fa18b99730f681ed299c9d75458d0e76af3c29f76c1f1a93957720311e30' 
  AND token = '3KOYf0hVN5y3vBck0iwDcaeZl+bDzwFcwVtMZ8DjKG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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