Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6d81516d175077c7dcb73c0b00e1a6da3f9c556d844e7aaf1e0e58b0bbf252d' 
  AND token = '7rFnSeZ2hytuy2MJPf5vwAdcUyt4RRhEQ/9UQ9NER4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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