SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4af53d4827229da77eca4bc93a3aa6cc8ace2326d23abaa2e762630322eb163' 
  AND token = '8q2l6ItJzSL/q5Gr/r/S1S5eaXuedHc+cIyWq4FWiE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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