SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '825e7b1080577286bd9c24611408fb956e13a654f444d7c454424af70251d1d3' 
  AND token = 'kxz8rrueFjRv1+LM0rxLKVdnLbnBNE+8mryYRkzrr4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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