SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5851831c77b675c8cd6b3ad736f116b97e73ca33e3450a971411fe4dc21c0be0' 
  AND token = 'r0F6Lgc+NjSA5vH63HsLAlVP2wvdg7Puyk+nZNdsgJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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