SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd129714585cffc945956de621db3d7dd7047863098484d1b88cb3d4eabe1d1a4' 
  AND token = 'Xr4wnawUsdhEgyXuU4BsG5BMCO4ZIEthwFNw7DCWK1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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