SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0481aa1f8e12a495c3e0b75097d380335705ffd490d1f0cc2ada1994171638f6' 
  AND token = 'wI8XPIOpkSsc0GvgD0oAZQ56iqpwBGt2uKnwD6f3VwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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