SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8be3c9427dbdfb9754079f03dbae966de192c31fe5d69c00fb5101b974561052' 
  AND token = 'WmcwaIdj7WrxLcRFrlZLRXfyJmmL4Fozzm5Ft8mxEZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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