SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b5a84f3b9be5e9240ee338963760925cd05d1fcb2335f0f881bd13d80f817163' 
  AND token = 'uPSG1aj1UQjAYiLKan4VSnN2+kbgGp13fHzApSj/mLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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