SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83a27ea9a5c7fa1e25a69d2cd738c77bb7366fee9a4a34d43dbf3a8c3acf3951' 
  AND token = 'cDLbhciO192Z4Zj37sZGEE5CYm96cQQmsuL6rOLxakA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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