SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8fab00a6d5592298861783f9f7642e97cb622b40ba75bddbf051223d6e28da22' 
  AND token = 'w4w/axBHpTCs0inS+LjKE2WjOEY0MnBWG1yqeGfRZ/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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