SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ee854856cf4510853531eba41a190adf10cc5b1be077fd2765f365dd1c2415be' 
  AND token = '0efPlPBunFFaOPU9qvRN6TouDkwc8cbLWkB42JJXubk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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