SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f696d4b27f93847fc4f24b01ae38bc253b243b159d35c5e95fda7c85f38b361' 
  AND token = 'VcRQNU9Tby+eW++ivw25FOY7emO+cf/JguWssTWph9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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