SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f4501ed0b481e686475654858b4b40096d31d83b00589ef6d821027c7b08d27c' 
  AND token = 'XKoGBiyxikI+DP0HGZ/WIjWCaEACCG4vRmWVEL6AbGc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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