SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64706800273706277f95d025d782e010cb072d7a847e8ada546c78fbb7a8faae' 
  AND token = 'oWWghu6mZirurPUFpvoMAVLrIt7EwSiOTmsIu/Tto00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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