SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2220f0fe0a8ce30df072928ea1754e8cbcd1e0939030a93094172e54b2843114' 
  AND token = 'v6frIjiSLI8BmXqRJHlSOCmn63XzeQdSWNyWjgeI2nk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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