SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3d47154d632eca9c2253a58a6672f33a5b7227f8d436bb6910bc778201af8e3' 
  AND token = 'yxi5CS5FdXKQk/crjaVB+ZCLiUJvI6p53h9pIxiYNaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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