SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '74d0b97fc15a6ef793e871cad1fe1e18436ff39d3940ce3c526d2cf5666130e4' 
  AND token = 'aA/3YlqGriKgFK44rbgi7Z0ZB4i04JPTnTbylkb33Ww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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