SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eca1c4a1e3ab244218fcba93c3e10a60e9c86cced6776574498da4ad248779dc' 
  AND token = 'jlcSNgDqR+OdaNgRJ3PT0mK/3NHDJKZOgFPaSjCUbGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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