SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '40e64d19ebd01cfbed718e1069d3b41f7a1fe4a33b2dc10f17bacb6647d396a5' 
  AND token = 'MMUG3snJXJRkAABmVtLURQXKqH5h8uaZD0VeRvq8gPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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