SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9ec1c1ec9678025ed6e85807afe3427bf590caa2eb50f0b8678bbe24d366e8f' 
  AND token = '2MwgF1GvP+0NQYnAPOYtvG5W8Ty6zQVLWT/hbYNsJsU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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