SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '877b6e3e813df47416e63cfc4dcf80a99b0fd55d13ffc30924902a2304baab97' 
  AND token = 'Yai4C4CiLd9nKzisyA8nhvd6d2XZD/Bl/i81wPGtVLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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