SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd61298f7c7b7e9de4ebb08e0a51421c0405d03be9766b23ef90c635d9c28046' 
  AND token = 'vIgwjnLeSwVidiLRCLquCSzKi1aHPqdOwD18p3FlOIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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