SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '818cabaab183c160eab26b65cf0c88a15b5b348f632efe07158d8a314a227ed7' 
  AND token = 'hLbrgV0r0uInT4IAmvFlVSmtyWltUYRGPcu+p1n1m4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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