SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fc49956506e337b26a6a825c6368a0323023dfef69f7b4db303a0ba477e17ff' 
  AND token = 'ULIrO54aZOdMrJDlG2EpjBIJAsWzUDjquD0EoOZFxPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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