SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90fed3fcaa75cb231127b8061c20fc9726f73c8c2324d0e58d79e5c1672034c5' 
  AND token = 'xFL+OZ+tmB9n6gO7Uak3bTdpdrcmGIXIsMXRXZUwmOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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