SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3afecfb8901a4d867851da54915623e526bc5835234aad1c40885eaa993dad11' 
  AND token = 'jnwBi9XCGkG+MwnzS9Q4KsHdpRQ+tWibKzKQZxqDMJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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