SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ac30726a4305e4241f7120aee8e7d9ccf8c5c96fafcd63d9beca974eec38bf1' 
  AND token = 'GLtmcF+RDJ2O8VgDShzMxVhGvYkLje8zZ9yynICpxX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}