SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b539848b145b0ad1b06acd86320d3bcbdccdd8b7d49bfdb56b0d440c76f2809' 
  AND token = 'bteBp9xjYo/95LrWwzxVHRduyAHVNPUsIQY6EE8VzDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}