SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '329ca95bb9e1fa9c3265b004a13bbcc7994748664f87060a580c1b8eb7559e29' 
  AND token = 'QGWDqmrkQRIlXcFCbjMKkYYMxAu0iyflCDUYGNaol2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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