SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4aca9245100aaa8053fc8697dce7fafe5de3e016826ec9727d3b2d47435358cf' 
  AND token = '5lg6CKARUglxlnblOuuHMZNtyYlrxvwwMyUYhgUf4iA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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