SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '906aab5afe553e4abff8db5d88a1f1742bb46a678b72e1cc2777b68b5e6e1daf' 
  AND token = 'WmtMcbrqp7k/pzs+nFPPCTcUAJbUL4Kuc8YWX+3Eipg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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