SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eabe246edba99e5df78fcc164fc5829b3aa33d67272d807c29d9222a3d3752e5' 
  AND token = '3HoVnaAlCYqKUQkhLj1sun4vVH+3mLHmmpTpBu+lFKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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