SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee6a20f20a3e46bfb3ed7c0f95733bb24c3e467dbb13f89b82f795208a2b3c2a' 
  AND token = 'kPjR24mC9R5GmwgH9lpxkGYwiDbgj7B8YXJF6Yc+0EI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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