SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '405a2cbe62ddb8111bf5ed072ae744e5bfd75fe15838cb5ba0a00e61a36e6881' 
  AND token = 'WKsbZHSDEdfpbgI3Af/gYv/DoglrUPePGihj+j7DKhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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