SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f91574d3c6dcd29ab43631bc8c6234dc6af39b58210006e5de686807f020710' 
  AND token = '951HECELLZNQAdk/icp5Bx8HG8YDnZu4gZagokg1iYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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