SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6db32d430d36299e9f5e2c4125c4e04bf04afbb3de2f29517bdcbc0f38231c91' 
  AND token = 'XSoU613gliheikwHFtk3kUEPQ3xb45Aae1qSx6Cz8pA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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