SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37a259ac46006a545db4d9549785665448592e7296a292edad533fa61ef906cd' 
  AND token = 'fLZ3gSE0P0dJpncDgFTF/CdKU3wg6YiI27Ysg1Vlarc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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