SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3bf4a664d48a548ff004af1f70e111686b59b245d589d2df0e7ab8f54f7c1a7' 
  AND token = 'GgHnZ0lG6F4JnKAj21Wg5YT3PbuIRvPLRL1lATE9UPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}