SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05f5f588d02bb45270bb9562c6b4f63900c550cf78ca2ee57c18179afe4eafb2' 
  AND token = 'QhC7UR/z6OTNgnrYdyk4dfK7qNrg33HCOw+MA7Y49DY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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