SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '832fdfbd68a4e4f88127452b3544db92f5bdb3d5eebfd3075437a59d7c4637f1' 
  AND token = '/9BB7+7zrjWxf5oNX4heCMpak+MCWmD05YGRhRPZPUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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