SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '663c9d8d91d98f444068339f2d573af8a2c107082006f4fb475b84684d2ba3f6' 
  AND token = '77XdfPq/qwLOlcupJX+w2EgiKRJjcv2W5B7WElc868k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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