SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b17b7962857318c1a43a1478cd4d94ea10cfe4b4d1396fceea957dec79dff288' 
  AND token = 'TtyNVhVmnmAYStUwuBgtNeR8v83zFB6dnKaTIoaEBOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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