SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d620eead38a7e9ec53716a1769a638785239dd2322fbf6a3d217db7e8f3dd2b' 
  AND token = 'wgg3gA+t2X/2YPB8Z1vgHG0bZDGHMqcKDRjfmFhQJXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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