SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2f845763af042dc637e33b7dc37000da4bd2b64ba0f9953919bc1d7eb2bfc87' 
  AND token = 'ISetfnDA+fQPVRchXkf0yHOqotFOxYlSrHxwbqa+FrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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