SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5caafc8770ea1826c84767bd7426ebb309f9dacce76244b26b874c34133131ca' 
  AND token = 'oFFEwKVH1ZZJQyn24KhKEEzj+/ys/v3qYJPuQoWfr0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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