SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f95287517a8896dba17a228366b20ae508fbbd8d887029699b589ba2f8750aa3' 
  AND token = 'BE8NigookE1/XwrFu/NPXaVCgfMNBEW/WMlpjWVfwwM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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