SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9133a5998b4ad3010363318788212a1fc0a2ff41014d88683bfb835c1ccb73a' 
  AND token = 'ZsNdodW4jEPC5orXY0vXeXuwYJ1QB+M6o4f3hTrwfhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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