SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4dd65f56bf3dc51ba9ef6fcdab2a50bae89e51e23273ae09bcaf861b91ebbc85' 
  AND token = 'jTHLFjH+Fj4XjwKL6vZUyjvVByVY8hO+JW2YNyCK02A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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