SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '372729182fe74faa8aadba93ad41858c2400301f0b5786fd4468a74a7a95fd11' 
  AND token = 'huwhoJEOxRM0/QUnR0kW0zb0cgL7uaMcm8wEsrMquzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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