SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94c3450040f47b1dbbe8935e90fb17badc62b9c08dad1e76ce8b431dd321c669' 
  AND token = 'frBlsOQXD9Yxz1beYOj/FSkRCSzrxYx/6moalsS6Wbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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