SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2ef295178f412cf9f40d9158b3f263cd2834a9f3ee919d76ce87a5f1454d390' 
  AND token = 'kWFIQs8QUcHegPvn9dDa6Uj5YgEYNhAI4g3kWX+6DbA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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