SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4baa2ad21d72da75a26cc1a6012227f1f9396a409f4930647c50ffc82bf9b810' 
  AND token = 'dpNDEN3fxRvTCqeOjFVamPqPdWYVTPhUlgMyiej4wzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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