SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55bc407b18945248cc8952045fb8190966db29ac089274e54e03e203fd99abbe' 
  AND token = 'AZ68HeQvGQAN/s4OorkuTVkaqaUpgQUmxQl6eWvsXIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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