SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9815f25a28308944c94e22b47105a4a6aa4763d0432268dfd4a2570c080a96d0' 
  AND token = 'b2EiFD7+UGnKbOl6Gd7dnYcXkZbq4eIzGfeSJhwNCHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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