SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f80f50cbd96f817897d9b58a36dff1bc9be832bd8e210272eb15fa2ef2f4de4' 
  AND token = '5jZA+/K1BmBWY87Z8Csz0qVJhr3ocZs6iIzlmWcCXzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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