SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7c3707dc571045c34a2e12bdc84e1ebb03e7f7215396b3c815efa716c127ccd' 
  AND token = 'JxvY2l6vI3CGsXEaYlwPhIOgZe1s4GHGCIbd+b23/YY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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