SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d6f747ffdb63b94afe31b1185c9526aaed9985b1144974ba1a68a7cd90661b6' 
  AND token = 'Eia1MVp+0FjW+FOfltvopbllsMhKSBxmZYc0VJJobGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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