SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17d73cc8afea111d379cbf02ffc75dc44706599a522fa98ea492556914180a76' 
  AND token = 'Vnx0QZamCDleThcZGy9gcYpY2nF/pKUIbdjxP8IShCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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