SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e055c9541a51917b6dab4750e09ef8171ccdd81716f8f1446b8630eee44fd1eb' 
  AND token = '0Xqos57kNjopavVl5Q3ARe0Dx1647afZKWNXZrRBK8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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