SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71044fad2a6d8c529ee9a537899680be87b37f67c127b9bc7c76a280b55dc761' 
  AND token = 'R1ulbt81OsEXTkxvNP8kZV5QUeMXvvvmqWwHucqLBqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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