SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45642d8064a578b9c60aaee94e2435e38f4740baa38dcfa91953adb7f66b5c7e' 
  AND token = 'nJvh6l9q1dt2CLmHTQ5+WZfpiwtsZXsK2vl9HvzkMJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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