SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '668ff5b9fd2a7124b121aafc90de0b15c0663c698de886ceb89fc5f4eadf1699' 
  AND token = 'sTQEgOz6NYY0WW0nqrroE5zEJ7kppFylpJEC0a03eiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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