SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23f1b0d200bfb35371b89a5b30039228d71f9c4d9dd5a36a8bd401825b74ba91' 
  AND token = '+TQJqD3qekRkRqDVU78wuzK4yrU/r6tQ94gw5YtlTNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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