SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61574f22f954e9d533eb6cd316f61f8652816e8ad5cb418c0150d29d8d7efe75' 
  AND token = 'PKu9KvYkkItiVMIzfIj4UUMThgpLLFF7FRoVAQTVeLQ=' 
  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"
    }
  }
}