SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f9909fea654f8981e07d228dc9e616943bf5f26fe1d4c0084868404a12965fd' 
  AND token = 'Hx4DZJzyNXC5n30y1H77f5zFY4ikGw+EknCznmMqAYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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