SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '586377136a5bebe27f251718c04ec86f5585e243def81497b8e7190ab45645e9' 
  AND token = '/H4A7C9C5/OhOujJ+7vfXQESzAjGKZYD8GuLARnFMbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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