SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70c9408bdf446252b0c2cd3e3b48ca35dbb178412746e115ee850b15e2a4fb51' 
  AND token = 'Iugm2LMwf2V2NskJGbMgDnG85MJJe+xUMGbs0m35kug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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