SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74ad4e399c22296ddc8f5bf8533700a11e3128e114f673508726a82ddc264bbc' 
  AND token = 'Jg83dwAj7yF1dx0mOv2k8byjjXaFiEb4NGSnp0DUb/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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