SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34771685a36a5bc245ea4175c058fe4fad2b1727476aa89bc563a34cee92eeca' 
  AND token = 'N8f5L0spThnu6fkHGM7EKBrNDanayS9RvNbjHUUh+0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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