SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2554fd1628304f221e6f9d8dabc373a08a39bce6701cb9f370ab5f158ae0a465' 
  AND token = 'PJXgqQ2Y+6CEnI8KZHJ8pVMtyZNgnH+k2y4bFzhotx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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